Mail: admin@qmedicine.co.in



Laryngeal (Throat) Cancer

throat cancer

Most cases of cancer of the larynx occur in people aged over 60. The common early symptom is a persistent hoarse voice. Many cases are diagnosed at an early stage when there is a good chance of a cure. In general, the more advanced the cancer (the more it has grown and spread), the less chance that treatment will be curative.

What is larynx?

The larynx is the top part of the trachea (windpipe). It is also called the voice box. You can see and feel the front part of the larynx as the Adam's apple on the front of the neck, just below the chin.

The larynx contains the vocal cords. These are V-shaped ridges of muscle tissue on the inside lining of the larynx. They vibrate when air passes between them to produce speech.
When you breathe in, air passes into the larynx and down the trachea towards the lungs. When you swallow, the larynx moves upwards slightly and a flap of cartilage tissue at the back of the tongue, called the epiglottis, closes over the entrance to the larynx. This ensures that food or drink go down the oesophagus (gullet) and not down the trachea.

What is cancer?

Cancer is a disease of the cells in the body where the abnormal cells multiply out of control. A malignant tumour is a lump or growth of tissue made up from cancer cells, which continue to multiply. Malignant tumours invade into nearby tissues and organs, which can cause damage. Also by invading blood vessels these cancerous cells can be deposited to other parts of the body, leading to secondary tumors (metastasis) in different areas of the body. Some cancers are more serious than others; some are more easily treated than others; some have a better outlook (prognosis) than others.

What is cancer of the larynx?

Cancer of the larynx is sometimes called laryngeal cancer. Some people also call it throat cancer. However, the throat includes the larynx and other nearby structures. Cancer of the larynx is just one type of cancer that can occur in the throat. Cancer of the larynx is common in the India with around 2,000 cases developing each year. It is four times more common in men than in women. It is rare in people aged less than 40 years and is most common in people aged over 60 years.

There are different types of cancer of the larynx:

Squamous cell carcinoma of the larynx occurs in more than 9 in 10 cases. This type arises from cells which are on the inside lining of the larynx.

Other types. There are some rare types of cancer which arise from other types of cells within the larynx. For example, adenocarcinoma of the larynx arises from cells in the tiny glands in the wall of the larynx that make mucus. There are some other very rare types.

What causes cancer of the larynx?

A cancerous tumour starts from one abnormal cell. The exact reason why a cell becomes cancerous is unclear. It is thought that something damages or alters certain genes in the cell. This makes the cell abnormal and multiply out of control.

Some people develop cancer of the larynx for no apparent reason. However, certain risk factors increase the chance that cancer of the larynx may develop. These include:

  • Ageing. It is more common in older people. Most cases are in people over 60.
  • Smoking. The damaging smoke passes through the larynx to get to the lungs.
  • Drinking a lot of alcohol, especially spirits.
  • A poor diet may be a risk factor, especially a diet lacking certain vitamins and minerals.
  • Long-term exposure to certain chemicals, fumes or pollutants may irritate the larynx if you breathe them in and may increase the risk.
  • Human papillomavirus (HPV) has been shown in some studies to be associated with cancer of the larynx.

How does cancer of the larynx present?

A hoarse voice is often the first symptom because most cancers of the larynx first start on, or close by, a vocal cord. The problem is, a hoarse voice is a common symptom of laryngitis (a viral infection of the larynx). Most people with hoarseness do not have cancer. However, laryngitis usually clears within a week or so. Therefore, see a doctor if you develop a hoarse voice which does not go within 2-4 weeks.

Other symptoms that may occur as the tumour grows in the larynx include: a lump in the throat, pain in the throat when swallowing, difficulty with breathing. These symptoms may occur before a hoarse voice develops if the tumour does not start next to the vocal cords.

If the cancer spreads to local lymph nodes (lymph glands) then the nearby glands in the neck will swell.

If the cancer spreads to other parts of the body, various symptoms can develop.

All the symptoms can be due to other conditions, so tests are needed to confirm the diagnosis.

How do you diagnose  and assess cancer of the larynx?

Initial assessment

If a doctor suspects that you may have cancer of the larynx, he or she will refer you to an ear, nose and throat (ENT) specialist. The specialist will examine the inside of your throat by using a small mirror and light. He or she may also use a thin, flexible, telescope (a nasoendoscope). This is passed into your nose and down the back of your throat. The nasoendoscope contains fibre-optic channels, allowing light to shine down so the doctor can see inside. (The throat is usually sprayed with a local anaesthetic before using a nasendoscope so the procedure is not too uncomfortable.)

To confirm the diagnosis

If anything suspicious is seen by the examination or with the nasoendoscope, you will usually need a biopsy. A biopsy is when a small sample of tissue is removed from a part of the body. The sample is then looked at under the microscope to look for abnormal cells. The biopsy sample is obtained by a thin, flexible grabbing instrument which is passed through your nose into the larynx. The same instrument has a light source similar to a nasoendoscope and so the specialist will also examine the trachea and oesophagus to see the extent of any tumour.

Assessing the extent and spread (staging)

In addition to the above tests, if you are confirmed to have cancer of the larynx then further tests may be done; for example, biopsy samples may be taken from the nearby lymph glands by using a fine needle. This helps to assess if any cancer cells have spread to the lymph glands.

Other tests may be arranged to see if the cancer has spread to other parts of the body. For example, a CT scan, an MRI scan, or other tests. (The separate leaflets describe each of these tests in more detail.)

This assessment is called staging of the cancer. The aim of staging is to find out:

  • How much the tumour in the larynx has grown.
  • Whether the cancer has spread to local lymph nodes.
  • Whether the cancer has spread to other areas of the body (metastasised).
  • Grade of the cancer
  • The biopsy samples are looked at under the microscope to asses the cancer cells. By looking at certain features of the cells the cancer can be graded.

The common grading system used for cancer of the larynx is:

  • Grade 1 (low grade). The cells look reasonably similar to normal cells in the larynx. The cancer cells are said to be well differentiated. The cancer cells tend to grow and multiply quite slowly and are not so aggressive.
  • Grade 2 (intermediate grade).
  • Grade 3 (high grade). The cells look very abnormal and are said to be poorly differentiated. The cancer cells tend to grow and multiply quite quickly and are more aggressive.

By finding out the stage and grade of the cancer it helps doctors to advise on the best treatment options. It also gives a reasonable indication of outlook (prognosis).

How do you treat cancer of the larynx?

Treatment options which may be considered include radiotherapy, surgery, and chemotherapy. The treatment advised for each case depends on various factors such as the exact site of the primary tumour in the larynx, the stage of the cancer (how large the cancer is and whether it has spread), the grade of the cancerous cells, and your general health.

Radiotherapy

This is the common treatment if the cancer is small and has not spread from the larynx (early stage). Radiotherapy is a treatment which uses high-energy beams of radiation which are focused on cancerous tissue. This kills cancer cells, or stops cancer cells from multiplying.

Radiotherapy alone gives a good chance of a cure if the cancer is at an early stage. Radiotherapy is also sometimes used in addition to surgery or chemotherapy in certain situations. For example, radiotherapy may be used to shrink a large tumour prior to surgery. This may give a better chance of success with surgery. It is sometimes used following surgery, to kill any cancer cells which may have been left behind following the operation.

Surgery

Tumours which are larger tend to require surgery. Sometimes surgery is aimed at curing the cancer by removing it all. Sometimes surgery is used to relieve symptoms if the cancer is at an advanced stage (palliative surgery). The operations are all done whilst you are asleep under a general anaesthetic.

The type of operation done depends on the size of the tumour, the exact site of the tumour in the larynx, and whether the cancer has spread to nearby structures or lymph glands. For example:

Endoscopic resection. This is a technique which can remove a small tumour in the larynx. Instruments are passed down the inside of the larynx which cut out a tumour. Sometimes a laser is used to burn out the tumour. This technique does not involve a cut from the outside. It is only suitable for tumours that are small and still confined to the inner lining of the larynx.

Partial laryngectomy. This is an operation where the affected part of the larynx is cut out. A cut is made in the front of the neck to get at the larynx. If only part of the larynx is removed you should not need a permanent stoma (hole in the neck) to breathe, and speech may be preserved. A temporary stoma may be required whilst the wound is healing.

A total laryngectomy. This is an operation where the entire larynx is removed. To be able to breathe after the operation, the top part of the trachea is attached to the front of the neck. You will then have a permanent hole (stoma) in the front of the neck. The vocal cords will have been removed so you will not be able to speak normally again. However, there are various techniques that you can be taught by a speech therapist which can enable you to make sounds and speak in a different way.

If the cancer has spread, the surgeon may also remove lymph glands and other structures near to the larynx in addition to removing the larynx. The amount of tissue removed depends on the extent of local spread of the cancer.

Chemotherapy

Chemotherapy is a treatment which uses anti-cancer drugs to kill cancer cells, or to stop them from multiplying. Chemotherapy used in conjunction with radiotherapy is sometimes used as an alternative to surgery. It aims to preserve the larynx and normal speech. Your specialist will advise when this may be an option. Chemotherapy may also be advised if the cancer has spread to other areas of the body.

Other treatments

Cetuximab is a fairly new treatment for laryngeal cancer. It is a type of monoclonal antibody which means that it can recognise and bind to specific proteins (receptors) that are found in the cancer cells. These proteins are epidermal growth factor receptors (EGFRs) which stimulate the cancer cell to grow and divide. Cetuximab locks on to the EGFR and can prevent the cancer cells from growing and dividing.

Cetuximab is a treatment that is usually given at the same time as radiotherapy in people who are unable to have chemotherapy.

What is the prognosis (outlook)?

If a cancer of the larynx is diagnosed and treated at an early stage then there is a good chance of a cure. A cure is less likely if the cancer has spread.

The treatment of cancer is a developing area of medicine. New treatments continue to be developed and the information on outlook above is very general. The specialist who knows your case can give more accurate information about your particular outlook, and how well your type and stage of cancer is likely to respond to treatment.


Alphabetical Index of Health Topics

If you already know your diagnosis, you may search for the health topic alphabetically here. Hold your cursor over the health topics link in the line below.

Write A Comment

 

Topic of the Month

Womb Transplant

womb-transplant

The new game changer in infertility. Know more about this revolutionary technique.

Continue Reading »

Health Video of the Month

Womb Transplant

Disclaimer: This health video may contain graphic material and viewer discretion is advised.